Just because they appear to be okay and light up, doesn't mean that they are
The best way to be sure is to swap them out with known good ones.
I have a 2100B myself, which had previously been used by a CBer and had been
abused by overdriving. When I got
it, the tubes lit up and appeared to be fine. However, the amp would only
put out 100 watts ...
I put in known good tubes and it has been pumping out 600 to 700 ever since...
> From: firstname.lastname@example.org
> To: email@example.com
> Date: Sun, 8 Jan 2012 07:52:14 -0700
> Subject: [Amps] FL 2100B OUTPUT PROBLEMS
> I recently purchased a FL2100B and initial setup and loading, the maximum
> plate current was 250ma.
> After tinkering with assorted levels of input from my exciter (775dsp) up
> to 100 watts, the AMP was
> able to draw less and less plate current and finally, little to none on any
> band. Loading and plate tuning had
> little effect on output as monitoring on external SWR cross needle Bridge.
> Pulled the tubes, they were PENTA LABS coded 9602, both. No physical
> indication of damage and filaments do
> Any thoughts would be appreciated.
> Dr. G. Carl, W7BQ
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